Eye PainNCT05931250
Alternating and Direct Current Stimulation for Neuropathic Eye Pain
A study testing DC-Stimulator Plus (NeuroConn GmbH, Germany) and Sooma direct current stimulator (Sooma, Finland) in people with Eye Pain and Neuropathy, Optic, run by Neil Lagali at 1 site in Sweden.
Trial summary
The goal of this clinical intervention is to test if two forms of transcranial current stimulation, transcranial direct current stimulation (tDCS) or transcranial alternating current stimulation (tACS) can alleviate neuropathic eye pain in a sample of 20 patients. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Eye Pain, Neuropathy, Optic, Cerebral Injury
- What is being tested?
- DC-Stimulator Plus (NeuroConn GmbH, Germany) and Sooma direct current stimulator (Sooma, Finland)
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteSweden
- Study dates
- 16 Jun 2023to 31 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- persistent eye pain for at least 6 months
- average eye pain intensity of 4 or more on a 0-10 numerical rating scale
- naive to transcranial stimulation
- eye pain having neuropathic-like characteristics
Who cannot join
- contraindication to transcranial stimulation (i.e., pacemaker, cardioverter defibrillator, neuro-stimulation (brain or spinal cord), bone growth stimulations, indwelling blood pressure monitors, epilepsy, pregnancy)
- presence of ocular diseases that are the likely cause of pain (i.e., corneal and conjunctival scarring, corneal edema, uveitis, iris transillumination defects, etc.)
- current participation in another study with an investigational drug or device within one month prior to screening
Trial locations and contacts
1 site in 1 country.
Sweden1 site
Eye Clinic, University Hospital in Linköping
Linköping, Other / Non-US, 58183
About this study
Official title: Alternating and Direct Current Stimulation for the Treatment of Chronic Neuropathic Eye Pain and Cerebral Symptoms: a Pilot Study
The goal of this clinical intervention is to test if two forms of transcranial current stimulation, transcranial direct current stimulation (tDCS) or transcranial alternating current stimulation (tACS) can alleviate neuropathic eye pain in a sample of 20 patients.
The main aims are:
Read more
- Test if tDCS/tACS can alleviate neuropathic eye pain and/or other cerebral symptoms: brain fatigue, migraine, light sensitivity, etc.
- Test if one stimulation method is superior to the other Patients will be treated for a total of fifteen 30-minute stimulation sessions, three times a day over a five-day period, each stimulation separated by approximately 4 hours, with either active tACS or tDCS over the scalp corresponding to primary sensory and motor areas.
The patients will have questionnaires to monitor subjective experiences and pupillometry before and after treatment to monitor experimental outcomes.
Read the detailed description
Brief Summary sufficient
- Conditions
- Eye Pain, Neuropathy, Optic, Cerebral Injury
- Being tested
- DC-Stimulator Plus (NeuroConn GmbH, Germany), Sooma direct current stimulator (Sooma, Finland)
- Medical subject headings
- Eye Pain, Optic Nerve Diseases, Brain Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DC-Stimulator Plus (NeuroConn GmbH, Germany)Device
Transcranial alternating current stimulation
Sooma direct current stimulator (Sooma, Finland)Device
Transcranial direct current stimulation
| Study group | Role | What they receive |
|---|---|---|
| Transcranial alternating current stimulation | Experimental | Transcranial alternating current stimulation (tACS) device using 50x70 mm electrodes that are placed bilaterally between EEG coordinates C3/C5 for left hemisphere and C4/C6 for right hemisphere (corresponding to S1 and M1 of the eye). The alternating current electrodes are in-phase and have the same peak to peak stimulation 3mA, for 30 minutes duration at 10Hz. An impedance value under 15 ohms is required at all times to ensure patient comfort and safety. Receives: Device: DC-Stimulator Plus (NeuroConn GmbH, Germany) |
| Transcranial direct current stimulation | Experimental | Transcranial direct current stimulation (tDCS) device using 50x70 mm electrodes that has the anodal electrode placed contralateral to most prominent ocular pain or, in the case of bilateral pain symptoms, contralateral to the dominant hand between EEG coordinates C3/C5 for left hemisphere and C4/C6 for right hemisphere (corresponding to S1 and M1 of the eye), and the cathode placed on the patient's upper arm. A current peaking at 3mA will ramp up for 20 secs and be delivered for a total of 20 minutes, thereafter, ramping down for 20s. An impedance value under 15 ohms is required at all times to ensure patient comfort and safety. Receives: Device: Sooma direct current stimulator (Sooma, Finland) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 1 week
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Measured: through treatment completion, 1 week
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 2 weeks
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Measured: through treatment completion, 2 weeks
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 1 month
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Measured: through treatment completion, 1 month
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 1 week
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Measured: through treatment completion, 1 week
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 2 weeks
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Measured: through treatment completion, 2 weeks
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 1 month
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Measured: through treatment completion, 1 month
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 1 week
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Measured: through treatment completion, 1 week
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 2 weeks
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Measured: through treatment completion, 2 weeks
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 1 month
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Measured: through treatment completion, 1 month
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 1 week
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Measured: through treatment completion, 1 week
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 2 weeks
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Measured: through treatment completion, 1 month
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 1 month
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Measured: through treatment completion, 1 month
Number of patients with treatment-related adverse events as assessed by ocular pain questionnaire
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Measured: through treatment completion, 1 month
Change from baseline pupil diameter in millimeters at 1 week
Minimum and maximum pupil diameter in millimeters
Measured: through treament completion, 1 week
Change from baseline pupil velocity in millimeters per second at 1 week
Pupil change velocity in millimeters per second
Measured: through treament completion, 1 week
Change from baseline pupil latency in milliseconds at 1 week
Pupil latency latency in milliseconds
Measured: through treament completion, 1 week
Secondary outcomes (1)
Treatment compliance rate
Evaluation of completed treatment from a total of 15
Measured: through study completion, 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jul 2023
- Study start16 Jun 2023
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Eye PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Neil Lagali
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital, Linkoeping, Linkoeping University, Region Östergötland
- Responsible party
- Sponsor-investigator, Neil Lagali, Region Östergötland
- Investigators
- Neil Lagali, PhD, Principal investigator, RegionÖstergötland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05931250
- Sponsor's protocol ID
- 20220727401
- Status last verified
- Jul 2026
- First submitted
- 16 Jun 2023
- Last updated
- 13 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Farhangi M, Feuer W, Galor A, Bouhassira D, Levitt RC, Sarantopoulos CD, Felix ER. Modification of the Neuropathic Pain Symptom Inventory for use in eye pain (NPSI-Eye). Pain. 2019 Jul;160(7):1541-1550. doi: 10.1097/j.pain.0000000000001552.
PubMed 30883524
Study at a glance
From the registry record, last updated by the sponsor on 13 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Alternating and Direct Current Stimulation for the Treatment of Chronic Neuropathic Eye Pain and Cerebral Symptoms: a Pilot Study
- ClinicalTrials.gov ID
- NCT05931250
- Acronym / sponsor ID
- 20220727401
- Conditions
- Eye Pain, Neuropathy, Optic, Cerebral Injury
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Neil LagaliUniversity, hospital or other
- Collaborators
- University Hospital, Linkoeping, Linkoeping University, Region Östergötland
- Study start
- 16 Jun 2023 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 5 Jul 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical intervention is to test if two forms of transcranial current stimulation, transcranial direct current stimulation (tDCS) or transcranial alternating current stimulation (tACS) can alleviate neuropathic eye pain in a sample of 20 patients.
The main aims are:
- Test if tDCS/tACS can alleviate neuropathic eye pain and/or other cerebral symptoms: brain fatigue, migraine, light sensitivity, etc.
- Test if one stimulation method is superior to the other Patients will be treated for a total of fifteen 30-minute stimulation sessions, three times a day over a five-day period, each stimulation separated by approximately 4 hours, with either active tACS or tDCS over the scalp corresponding to primary sensory and motor areas.
The patients will have questionnaires to monitor subjective experiences and pupillometry before and after treatment to monitor experimental outcomes.
Detailed description
Brief Summary sufficient
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Transcranial alternating current stimulation | Experimental | Device: DC-Stimulator Plus (NeuroConn GmbH, Germany)Transcranial alternating current stimulation (tACS) device using 50x70 mm electrodes that are placed bilaterally between EEG coordinates C3/C5 for left hemisphere and C4/C6 for right hemisphere (corresponding to S1 and M1 of the eye). The alternating current electrodes are in-phase and have the same peak to peak stimulation 3mA, for 30 minutes duration at 10Hz. An impedance value under 15 ohms is required at all times to ensure patient comfort and safety. |
| Transcranial direct current stimulation | Experimental | Device: Sooma direct current stimulator (Sooma, Finland)Transcranial direct current stimulation (tDCS) device using 50x70 mm electrodes that has the anodal electrode placed contralateral to most prominent ocular pain or, in the case of bilateral pain symptoms, contralateral to the dominant hand between EEG coordinates C3/C5 for left hemisphere and C4/C6 for right hemisphere (corresponding to S1 and M1 of the eye), and the cathode placed on the patient's upper arm. A current peaking at 3mA will ramp up for 20 secs and be delivered for a total of 20 minutes, thereafter, ramping down for 20s. An impedance value under 15 ohms is required at all times to ensure patient comfort and safety. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- persistent eye pain for at least 6 months
- average eye pain intensity of 4 or more on a 0-10 numerical rating scale
- naive to transcranial stimulation
- eye pain having neuropathic-like characteristics
Key exclusion criteria (3 listed)
- contraindication to transcranial stimulation (i.e., pacemaker, cardioverter defibrillator, neuro-stimulation (brain or spinal cord), bone growth stimulations, indwelling blood pressure monitors, epilepsy, pregnancy)
- presence of ocular diseases that are the likely cause of pain (i.e., corneal and conjunctival scarring, corneal edema, uveitis, iris transillumination defects, etc.)
- current participation in another study with an investigational drug or device within one month prior to screening
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DC-Stimulator Plus (NeuroConn GmbH, Germany)Transcranial alternating current stimulation | Device | Transcranial alternating current stimulation |
| Sooma direct current stimulator (Sooma, Finland)Transcranial direct current stimulation | Device | Transcranial direct current stimulation |
Primary outcome
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 1 week
Time frame: through treatment completion, 1 week
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 2 weeks
Time frame: through treatment completion, 2 weeks
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 1 month
Time frame: through treatment completion, 1 month
Assesses pain related symptoms on a scale from 0 indicating no pain (better outcome) to10 indicating worst pain imaginable (worse outcome)
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 1 week
Time frame: through treatment completion, 1 week
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 2 weeks
Time frame: through treatment completion, 2 weeks
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Change from baseline subjective pain effect experiences via Defense and Veteran Pain Rating Scale (DVPRS) at 1 month
Time frame: through treatment completion, 1 month
Assesses pain related symptoms effecting sleep, stress, disposition, life quality, on a scale from 0 indicating no effect (better outcome) to10 indicating maximum effect (worse outcome)
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 1 week
Time frame: through treatment completion, 1 week
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 2 weeks
Time frame: through treatment completion, 2 weeks
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Change from baseline subjective mental symptoms via Mental Fatigue Scale (MFS) at 1 month
Time frame: through treatment completion, 1 month
Assesses mental symptoms on a scale from 0 indicating no effect (better outcome) to 3 indicating extreme effect (worse outcome)
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 1 week
Time frame: through treatment completion, 1 week
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 2 weeks
Time frame: through treatment completion, 1 month
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Change from baseline subjective ocular symptoms and symptom frequency via custom ocular pain questionnaire at 1 month
Time frame: through treatment completion, 1 month
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Number of patients with treatment-related adverse events as assessed by ocular pain questionnaire
Time frame: through treatment completion, 1 month
Ocular pain questionnaire using a visual analog scale with 0 indicating no pain (better outcome) and 10 indicating extreme pain (worse outcome) and frequency measure from 0% indicating never occurring (better outcome) to 100% indicating always occurring (worse outcome)
Change from baseline pupil diameter in millimeters at 1 week
Time frame: through treament completion, 1 week
Minimum and maximum pupil diameter in millimeters
Change from baseline pupil velocity in millimeters per second at 1 week
Time frame: through treament completion, 1 week
Pupil change velocity in millimeters per second
Change from baseline pupil latency in milliseconds at 1 week
Time frame: through treament completion, 1 week
Pupil latency latency in milliseconds
1 secondary outcome
Treatment compliance rate
Time frame: through study completion, 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Jul 2026.
- Background: PubMed 30883524Farhangi M, Feuer W, Galor A, Bouhassira D, Levitt RC, Sarantopoulos CD, Felix ER. Modification of the Neuropathic Pain Symptom Inventory for use in eye pain (NPSI-Eye). Pain. 2019 Jul;160(7):1541-1550. doi: 10.1097/j.pain.0000000000001552.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Neil Lagali, PhD principal investigator
RegionÖstergötland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing DC-Stimulator Plus (NeuroConn GmbH, Germany) and Sooma direct current stimulator (Sooma, Finland) in people with Eye Pain and Neuropathy, Optic, run by Neil Lagali at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline subjective pain via neuropathic pain symptom inventory for the eye (NPSI-eye) at 1 week (time frame: through treatment completion, 1 week). The study lists 16 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05931250, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jul 2026.